What is class hierarchy in Java with example?

How many classes must be there to implement hierarchical inheritance? Explanation: At least 3 classes must be there.

Hierarchical inheritance is a kind of inheritance where more than one class is inherited from a single parent or base class . Especially those features which are common in the parent class is also common with the base class.

Java supports only Single, Multilevel, and Hierarchical types of inheritance . Java does not support Multiple and Hybrid inheritance.

The hierarchy of classes in Java has one root class, called Object , which is superclass of any class . Instance variable and methods are inherited down through the levels. In general, the further down in the hierarchy a class appears, the more specialized its behavior.